Memory: Factors Affecting Memory

What you'll learn

This revision guide covers the key factors that affect memory accuracy and recall, a core topic in the Edexcel GCSE Psychology specification. You'll explore how context-dependent memory operates, understand different types of interference, and learn why eyewitness testimony can be unreliable. These concepts are essential for explaining why we sometimes struggle to remember information or why our memories can be distorted.

Key terms and definitions

Context-dependent memory — the phenomenon where recall is better when the environment at retrieval matches the environment at encoding (learning)

Interference — when one memory disrupts the ability to recall another memory, either because similar information competes or new learning overwrites old information

Proactive interference — when older memories disrupt the recall of newer memories (old information interferes with new)

Retroactive interference — when newer memories disrupt the recall of older memories (new information interferes with old)

Leading questions — questions phrased in a way that suggests a particular answer or contains misleading information

Eyewitness testimony (EWT) — evidence provided by people who witnessed a crime or accident, based on their memory of the event

False memory — a recollection of an event that did not actually occur, or a distorted memory of an actual event

Anxiety — a state of emotional arousal and worry that can affect the accuracy and detail of memories formed during stressful events

Core concepts

Context-dependent memory

Context-dependent memory refers to the improved recall that occurs when the environmental context at retrieval matches the context present during encoding. This effect demonstrates that memory is not just about what we learn, but also where we learn it.

Key research: Godden and Baddeley (1975)

Godden and Baddeley conducted a field experiment with deep-sea divers to investigate context-dependent memory:

• Divers learned word lists either underwater or on land
• They were then tested in either the same environment or a different one
• Four conditions: learn underwater/recall underwater, learn underwater/recall on land, learn on land/recall on land, learn on land/recall underwater
• Results: Recall was approximately 40% better when the learning and recall environments matched
• Words learned underwater were recalled better underwater; words learned on land were recalled better on land

Explanation

Environmental cues present during learning become associated with the information being encoded. When these same cues are present during retrieval, they act as triggers that help access the stored memory. This is why students sometimes perform better in exams held in their usual classroom.

Limitations of context effects

• Context effects are stronger for recall tasks than recognition tasks
• The effect may be reduced when the material is very meaningful or well-learned
• Laboratory studies may exaggerate the effect compared to real-world situations

Interference theory

Interference theory proposes that forgetting occurs because memories compete with and disrupt one another. This is particularly likely when memories are similar in content or context.

Proactive interference

Old information learned previously interferes with the ability to remember new information:

• Example: Difficulty remembering your new mobile number because you keep recalling your old one
• Example: A Spanish student learning French may use Spanish words instead of newly learned French vocabulary
• The older memory is typically stronger and more established, making it dominant

Retroactive interference

New information learned recently interferes with the ability to remember old information:

• Example: Learning a new password makes it harder to recall your previous password
• Example: After learning a revised version of a theory in Psychology, struggling to remember the original version
• The new memory overwrites or disrupts the older memory trace

Key research: McGeoch and McDonald (1931)

This classic study demonstrated retroactive interference:

• Participants learned a list of words until they could recall them with 100% accuracy
• Different groups then learned different types of new material (synonyms, antonyms, unrelated words, nonsense syllables, numbers, or had a rest period)
• When retested on the original list, recall was worst when the intervening material was most similar (synonyms)
• Conclusion: Interference is strongest when memories are similar

Real-world applications

• Students should avoid revising similar subjects back-to-back (e.g., Spanish then French)
• Spacing out learning reduces interference effects
• Testing yourself regularly helps strengthen memories and makes them more resistant to interference

Misleading information and eyewitness testimony

Eyewitness testimony is often less accurate than people assume. Misleading information provided after an event can alter a person's memory of what actually happened.

Key research: Loftus and Palmer (1974)

This landmark study demonstrated how leading questions affect memory:

Experiment 1:

• Participants watched video clips of car accidents
• Asked "About how fast were the cars going when they [verb] each other?"
• Five groups received different verbs: contacted, hit, bumped, collided, smashed
• Results:
  • "Contacted" group estimated 31.8 mph average
  • "Smashed" group estimated 40.5 mph average
• The verb used systematically affected speed estimates

Experiment 2:

• Participants watched a video of a car accident
• One group asked "How fast were the cars going when they smashed into each other?"
• Control group asked "How fast were the cars going when they hit each other?"
• One week later, all participants asked "Did you see any broken glass?" (there was none)
• Results: 32% of the "smashed" group reported seeing broken glass vs. 14% of the "hit" group

Explanation: Substitution bias

Loftus proposed that misleading information actually changes the memory trace — the original memory is altered or replaced. The leading question doesn't just influence the response; it modifies the underlying memory representation.

Alternative explanation: Response bias

Critics argue that the original memory remains intact, but participants simply give the answer they think is expected based on the question wording. They may be guessing rather than genuinely remembering differently.

Post-event discussion

When witnesses discuss an event with each other, they can incorporate information from others into their own memories:

• Co-witnesses may influence each other's recall
• Witnesses may conform to what others report
• This is particularly problematic in police investigations where witnesses may compare accounts

Anxiety and memory accuracy

The relationship between anxiety and eyewitness testimony is complex. Extreme stress during an event can both enhance and impair memory, depending on the level of arousal.

Weapon focus effect

When a weapon is present during a crime, witnesses often recall the weapon in detail but remember fewer details about the perpetrator:

• Attention narrows to focus on the threatening object (the weapon)
• Heightened anxiety reduces the encoding of peripheral details
• Loftus et al. (1987) found participants had poorer recall of a person's face when that person was holding a gun versus a pen

Yerkes-Dodson Law application

The relationship between arousal and performance follows an inverted U-shape:

• Low anxiety: Insufficient arousal leads to poor attention and weak memory encoding
• Moderate anxiety: Optimal arousal enhances attention and memory formation
• High anxiety: Excessive arousal impairs cognitive processing and memory accuracy

Research: Yuille and Cutshall (1986)

This real-world study contradicts some laboratory findings:

• Interviewed witnesses of an actual shooting 4-5 months after the event
• Those who reported highest stress had most accurate recall
• Suggests that in real traumatic events, high arousal may enhance memory for central details
• However, peripheral details may still be poorly recalled

Evaluation

• Laboratory studies may lack the emotional intensity of real crimes
• Real-world crimes are unique events, making them potentially more memorable
• Ethical issues prevent researchers from creating genuinely high-anxiety situations in experiments

Age and eyewitness testimony

Children and elderly people may be less reliable eyewitnesses than adults, though this varies by circumstance.

Child witnesses

Research findings on child witnesses:

• Young children (under 5) are more susceptible to leading questions
• Children may confuse real events with things they've imagined or been told
• Children have greater difficulty with source monitoring — identifying where a memory came from
• However, when interviewed appropriately (open questions, no pressure), children can provide accurate testimony
• The Cognitive Interview technique is particularly helpful with child witnesses

Elderly witnesses

Older adults may experience:

• Greater susceptibility to misleading post-event information
• More difficulty remembering source details (context)
• However, motivation and attention at encoding can compensate for age-related changes
• Core details of significant events may be as accurately recalled as in younger adults

Worked examples

Example 1: Application question (4 marks)

Question: Explain how interference might affect a student who is revising for their GCSE exams in Biology and Chemistry on the same evening.

Mark scheme response:

The student may experience both proactive and retroactive interference (1 mark). Proactive interference could occur when information learned in Biology (the earlier subject) makes it harder to learn new Chemistry content, for example if similar terminology is used in both subjects (1 mark). Retroactive interference could happen when the Chemistry revision (learned later) disrupts recall of the Biology content learned earlier in the evening (1 mark). This is because the two subjects are similar and the information competes in memory, making it harder to retrieve the correct information for each subject (1 mark).

Example 2: Research methods question (6 marks)

Question: Godden and Baddeley (1975) investigated context-dependent memory using divers. Describe the procedure and findings of this study.

Mark scheme response:

Procedure (3 marks): Godden and Baddeley used deep-sea divers as participants (1 mark). The divers learned word lists in two different environments — either underwater or on dry land (1 mark). They were then asked to recall the words either in the same environment where they learned them or in a different environment, creating four conditions in total (1 mark).

Findings (3 marks): The divers recalled more words when the learning and recall environments matched (1 mark). For example, words learned underwater were better recalled underwater, and words learned on land were better recalled on land (1 mark). Recall was approximately 40% better when contexts matched compared to when they were different (1 mark).

Example 3: Evaluation question (4 marks)

Question: Evaluate Loftus and Palmer's (1974) research into leading questions.

Mark scheme response:

One strength is that the study used a controlled laboratory experiment with standardized video clips, meaning all participants saw exactly the same accident, increasing internal validity (1 mark). However, a weakness is that watching a video lacks the emotional impact of witnessing a real accident, so participants may not pay as much attention or encode the memory as deeply, reducing ecological validity (1 mark). Another weakness is that the sample was American students, who may not be representative of typical eyewitnesses, limiting generalizability (1 mark). A strength is that the findings have real-world applications for police interviewing techniques, showing the importance of avoiding leading questions when questioning witnesses (1 mark).

Common mistakes and how to avoid them

• Confusing proactive and retroactive interference: Remember the prefix — "pro" means forward (old interferes with new), "retro" means backward (new interferes with old). Create a mnemonic or diagram to keep them distinct.

• Mixing up the Loftus and Palmer conditions: Be precise about which verb produced which speed estimate. The word "smashed" produced the highest estimate (40.5 mph), while "contacted" produced the lowest (31.8 mph). Don't just say "different verbs" — name them.

• Oversimplifying the anxiety-memory relationship: Avoid stating that anxiety simply "improves" or "worsens" memory. The relationship is curvilinear (inverted U-shape) and depends on the level of arousal and whether you're measuring central or peripheral details.

• Not linking concepts to real-world applications: Examiners reward application. When discussing context-dependent memory, mention studying in the same room as your exam. When discussing interference, suggest revision timetabling strategies.

• Forgetting to evaluate research: In extended-answer questions, always include evaluation. Consider ecological validity, sample characteristics, ethical issues, and practical applications.

• Confusing substitution bias with response bias: Substitution bias suggests the memory itself is altered, while response bias suggests the original memory remains but the participant's response changes. These are different theoretical explanations.

Exam technique for "Memory: Factors Affecting Memory"

• Command words matter: "Describe" requires factual detail without judgment (e.g., procedure, findings). "Explain" requires reasons and mechanisms. "Evaluate" requires strengths and weaknesses with justification. Each command word signals different content.

• Structure your extended answers: Use the PEEL format — make a Point, provide Evidence (research/example), Explain how it links, and Link back to the question. For 6-mark questions, aim for approximately three developed points.

• Use research effectively: Named studies (Godden and Baddeley, Loftus and Palmer, McGeoch and McDonald) demonstrate knowledge and understanding. Include researcher names, dates when possible, key features of procedure, and main findings. This earns marks across all assessment objectives.

• Apply concepts to scenarios: Application questions present novel situations. Identify the relevant factor (context, interference, misleading information, anxiety), explain the concept briefly, then apply it specifically to the scenario details provided. Use words from the question in your answer.

Quick revision summary

Memory accuracy is affected by multiple factors. Context-dependent memory shows recall improves when retrieval context matches encoding context (Godden and Baddeley). Interference occurs when similar memories compete — proactive (old disrupts new) or retroactive (new disrupts old). Eyewitness testimony is unreliable due to misleading information altering memory (Loftus and Palmer) and anxiety affecting encoding, with high weapon focus reducing peripheral detail recall. Age affects testimony reliability, with children and elderly people more susceptible to post-event information. Understanding these factors has practical applications for police procedures and educational strategies.